| Posionjärvi | |
| Pushpin Map: | Finland Lapland |
| Coords: | 66.1333°N 30°W |
| Type: | Lake |
| Inflow: | Karisalmi strait, lake Posionperä |
| Outflow: | Ahvensalmi strait, lake Yli-Kitka |
| Catchment: | Koutajoki |
| Basin Countries: | Finland |
| Area: | 18.89km2 |
| Depth: | 2.42m (07.94feet) |
| Max-Depth: | 11m (36feet) |
| Volume: | 0.045km3 |
| Shore: | 146.46km (91.01miles) |
| Elevation: | 240.2m (788.1feet) |
| Frozen: | November–May |
| Islands: | Halkosaaret, Maaninkasaaret |
| Cities: | Posio |
Posionjärvi is a medium-sized lake in the Koutajoki main catchment area. It is located in Posio municipality, in the region Lapland in Finland.[1]
There are 187 islands in the lake.